Battery pack and power supply device

Abstract

The first problem that the present invention addresses is achieving a highly reliable battery by suppressing the flow of a large current between a battery cell and a battery pack during a salt water test and thus suppressing a sudden reaction caused by the large current. The following configuration addresses this first problem. An assembled battery 100 has a plurality of battery cells (unit batteries) 101, a first end member 102 that retains the plurality of battery cells 101 from one end side in a layering direction, a second end member 103 that retains the same from the other end side in the layering direction, and a linking member 104 that links the first end member 102 and the second end member 103. The linking member 104, which binds the battery cells 101 in the layering direction, and a connection member, which connects to a battery pack, are configured so as to be insulated from one another.

Description

[Technical field]

[0001] The present invention relates to a battery pack in which a plurality of battery cells are stacked. [Background technology]

[0002] An assembled battery of this type has been disclosed that has a plurality of stacked battery cells, a bus bar case fixed to the plurality of battery cells, and a plurality of covers that cover and protect the bus bar case (Patent Document 1).

[0003] Patent Document 2 describes a configuration in which a connecting fixture for connecting multiple battery cells made of iron or the like is used to fasten multiple battery cells in one direction using a connecting fixture made of metal such as steel plate. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] WO2012 / 164635 [Patent Document 2] Patent Publication 2015-111493 Summary of the Invention [Problem to be solved by the invention]

[0005] A configuration in which multiple assembled batteries are arranged in a metal container is called a battery pack, but when this battery pack is tested by immersing it in salt water, there is a risk of a short circuit occurring between the assembled batteries and the battery pack, causing a sudden reaction.The first object of the present invention is to provide a highly reliable battery that prevents a large current from flowing between the battery cells and the battery pack container via the salt water, thereby suppressing a sudden reaction, even when the battery pack is immersed in salt water.

[0006] In the battery pack described in Patent Document 1, when the number of battery cells is changed in response to demand, the overall length changes, and therefore the lengths of the busbar case, gas hose, etc. in the stacking direction of the battery cells and the positions of the electrode terminals, which are the locations for extracting power, also change.

[0007] The second object of the present invention is to solve such problems, and it is an object of the present invention to provide a battery pack that can minimize changes to the components even if the number of constituent battery cells changes. [Means for solving the problem]

[0008] The main means for solving the first problem is as follows: An assembled battery includes a battery body in which a plurality of unit cells are stacked, a pair of end members made of an insulating material and arranged on both sides of the battery body in the stacking direction of the battery body, and a pair of side plates made of a metal material and arranged on both side surfaces of the battery body in the stacking direction of the unit cells and connected to the end members, wherein the end members include fastening portions that accommodate fastening members that fasten the assembled battery to a mounting object, and the fastening portions and the side plates are arranged so as not to be electrically connected to each other.

[0009] The main means for solving the second problem is as follows: A battery pack includes a plurality of stacked cells, a first end member that holds the plurality of unit cells from one end side in the stacking direction, a second end member that holds the plurality of unit cells from the other end side in the stacking direction, and a connecting member that connects the first end member and the second end member, wherein the first end member protrudes a predetermined length toward the unit cells from a connection position with the connecting member in the stacking direction, and the predetermined length is equal to or greater than the thickness of the unit cells in the stacking direction. Effect of the Invention

[0010] According to the present invention, even when the battery pack is immersed in salt water, the current generated between the cell and the battery pack container can be mitigated, and a sudden reaction can be prevented from occurring. Even if a sudden reaction occurs, the effect can be contained within the battery pack. Even if the number of batteries is changed, the change in the components can be kept to a minimum. Further features related to the present invention will become apparent from the description of this specification and the attached drawings. Problems, configurations, and effects other than those described above will become apparent from the following description of the embodiments. [Brief description of the drawings]

[0011] [Figure 1] FIG. 2 is a perspective view of a battery cell according to the first embodiment. [Diagram 2] FIG. 1 is a perspective view of a battery pack according to a first embodiment. [Diagram 3] FIG. 2 is an exploded perspective view of the battery pack according to the first embodiment. [Figure 4] FIG. 2 is a plan view of a block of the battery pack according to the first embodiment. [Diagram 5] FIG. 2 is a plan view of a busbar case assembly of the battery pack according to the first embodiment. [Figure 6] FIG. 11 is a perspective view of a battery pack according to a second embodiment. [Figure 7] FIG. 11 is an exploded perspective view of a battery pack according to a second embodiment. [Figure 8] FIG. 11 is a plan view of a block of a battery pack according to a second embodiment. [Figure 9] FIG. 11 is an exploded perspective view of a battery pack according to a third embodiment. [Figure 10] FIG. 13 is an exploded perspective view of a battery pack according to a fourth embodiment. [Figure 11] FIG. 13 is a perspective view of a battery pack according to a fifth embodiment. [Figure 12] FIG. 13 is an exploded perspective view of a battery pack according to a fifth embodiment. [Figure 13] A diagram showing the configuration of a power supply device equipped with two assembled batteries each made up of multiple stacked battery cells. [Figure 14] A diagram showing the configuration of a power supply device equipped with four assembled batteries, each of which is made up of multiple stacked battery cells. [Figure 15]1 is a plan view conceptually illustrating one embodiment of a battery pack of the present invention. [Figure 16] FIG. 4 is a plan view conceptually showing another embodiment of a battery pack of the present invention. [Figure 17] FIG. 11 is a perspective view of a battery pack according to a second embodiment. [Figure 18] FIG. 2 is a perspective view of the assembled battery disassembled into a block and a busbar case assembly. [Figure 19] FIG. [Figure 20] FIG. [Figure 21] FIG. 21 is a side view of the block of FIG. [Figure 22] Cross-sectional view taken along line AA in Figure 21. [Diagram 23] FIG. [Figure 24] 13 is a cross-sectional view showing another configuration for fastening battery bodies in the stacking direction by side plates and end spacers. FIG. [Diagram 25] 13 is a cross-sectional view showing still another configuration for fastening battery bodies in the stacking direction by side plates and end spacers. FIG. [Figure 26] 13 is a cross-sectional view showing still another configuration for fastening battery bodies in the stacking direction by side plates and end spacers. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Next, the present invention will be described with reference to Example 1 and Example 2. Example 1 is an invention relating to a configuration that can minimize changes to the components even if the number of unit cells is changed, and Example 2 provides a configuration that can mitigate the current generated between the battery cells and the battery container and suppress abrupt reactions even when the battery pack is immersed in salt water. EXAMPLES

[0013] FIG. 15 is a plan view conceptually showing one embodiment of a battery pack of the present invention.

[0014] The battery pack 100 includes a plurality of battery cells (single cells) 101, a first end member 102 that holds the plurality of battery cells 101 from one end side in the stacking direction, a second end member 103 that holds the plurality of battery cells 101 from the other end side in the stacking direction, and a connecting member 104 that connects the first end member 102 and the second end member 103. The first end member 102 protrudes a predetermined length L4 toward the battery cells 101 from a connection position P in the stacking direction with the connecting member 104, and this predetermined length L4 is equal to or greater than the thickness L2 of the battery cells 101 in the stacking direction. Note that the reference symbol P2 in FIG. 15 indicates the connection position of the second end member 103 with the connecting member 104 in the stacking direction.

[0015] 15, by using an end member having a thickness different from that of the first end member 102 instead of the first end member 102, it is possible to obtain an assembled battery having the same external shape but a different number of battery cells 101. For example, by using an end member that is thinner by the thickness of one battery cell than the predetermined length L4 by which the first end member 102 protrudes, it is possible to form an assembled battery having a specification in which the number of battery cells 101 is increased by one. Also, by using an end member that is thicker by the thickness of one battery cell than the predetermined length L4 by which the first end member 102 protrudes, it is possible to form an assembled battery having a specification in which the number of battery cells 101 is decreased by one.

[0016] These assembled batteries differ only in the number of battery cells, and because the same connecting members 104 and second terminal members 103 are used, the size of the assembled batteries as a whole remains the same, and the external shapes are identical to each other. Therefore, there is no need to newly manufacture components such as busbar cases, gas hoses, and multiple covers to match the number of battery cells, and they can be standardized. Furthermore, even if the number of battery cells is changed, the assembly process and tools do not change, and there is no need to change the settings of the manufacturing equipment, allowing the sharing of facilities. Furthermore, there is no problem of an increase in the number of components and an increase in management man-hours.

[0017] Furthermore, for example, when two electric vehicles of the same model but with different battery specifications are to be equipped with assembled batteries each having a different number of battery cells, the assembled batteries can be installed without modification or with only minor modifications to the vehicle body structure for mounting the assembled batteries, allowing a common vehicle platform to be used. Furthermore, common vehicle components can be used without modifying the layout of electrical wiring or the layout of the exhaust gas passage for exhaust gas discharged from the battery cells. In addition, when it becomes necessary to increase the number of battery cells mounted on a vehicle due to a vehicle model change, or when it becomes possible to reduce the number of battery cells mounted on a vehicle due to improved battery performance, this can be easily accommodated without changing the size of the entire assembled battery.

[0018] FIG. 16 is a plan view conceptually showing another embodiment of the battery pack of the present invention.

[0019] The battery pack 200 includes a plurality of stacked battery cells (single cells) 201, spacers 202 stacked together with the plurality of battery cells 201, and a holding member 203 that holds the plurality of battery cells 201 and the spacers 202 in the stacking direction. The holding member 203 holds the plurality of battery cells 201 and the spacers 202 over a total length L1 that is a constant value determined along the stacking direction. The spacer 202 has a thickness L3 in the stacking direction that is equal to or greater than the thickness L2 of the battery cells 201 in the stacking direction.

[0020] 16, a battery pack having the same external shape but a different number of battery cells 201 can be obtained simply by replacing the spacer 202 with a spacer having a different thickness from the spacer 202. For example, by using a spacer that is one battery cell thicker than the thickness L3 of the spacer 202, a battery pack with specifications in which the number of battery cells 201 is increased by one can be formed. Also, by using a spacer that is one battery cell thicker than the thickness L3 of the spacer 202, a battery pack with specifications in which the number of battery cells 201 is decreased by one can be formed.

[0021] These battery packs are different only in the number of battery cells, similar to the embodiment shown in Fig. 15, but the overall size of the battery packs is the same and the external shapes are the same, so that the same effects as the embodiment shown in Fig. 15 can be obtained.

[0022] Hereinafter, a battery pack 10 according to a first embodiment to a battery pack 10D according to a fifth embodiment, to which a battery pack according to the present invention is applied, will be described with reference to the drawings.

[0023] (First embodiment) First, a battery cell 1 constituting a battery pack 10 according to a first embodiment will be described with reference to the drawings. As shown in Fig. 1, the battery cell 1 has a battery can 2, a battery lid 3, a positive electrode terminal 4, a negative electrode terminal 5, a gas release valve 6, a liquid injection plug 7, an electrolyte, a charging / discharging element, and an insulating case (not shown). A rechargeable secondary battery such as a lithium ion secondary battery is used for the battery cell 1. The battery cell 1 of the first embodiment corresponds to a single cell of the battery pack according to one embodiment of the present invention.

[0024] The battery can 2 has a rectangular parallelepiped shape with one end of the internal space open, and is made of aluminum or an aluminum alloy. The battery can 2 has a pair of opposing side plates 2a with a large area, a pair of opposing side plates 2b with a small area, and a bottom plate 2c on the opposite side to the opening. The internal space of the battery can 2 contains charging / discharging elements covered with an insulating case, and an electrolyte is injected. The positive electrode of the charging / discharging element is connected to a positive terminal 4, and the negative electrode of the charging / discharging element is connected to a negative terminal 5.

[0025] The battery lid 3 has the same rectangular flat plate shape as the bottom plate 2c, is made of aluminum or an aluminum alloy, and closes the opening of the battery can 2. The battery lid 3 is joined to the opening of the battery can 2 by a joining means such as laser welding. A liquid injection hole (not shown) is formed through the battery lid 3, and an electrolyte is injected through the liquid injection hole, which is closed by a liquid injection plug 7.

[0026] A gas exhaust valve 6 is provided in the center of the battery lid 3. When the battery cell 1 generates heat due to an abnormality such as overcharging, generating gas, and the pressure inside the battery can 2 increases and reaches a predetermined pressure, the gas exhaust valve 6 opens to exhaust the gas from inside the container, thereby reducing the pressure inside the battery can 2.

[0027] Further, through holes (not shown) are formed at one end and the other end of the battery lid 3, and a positive electrode terminal 4 and a negative electrode terminal 5 are attached to the through holes. The portions of the positive electrode terminal 4 and the negative electrode terminal 5 exposed to the outside from the battery lid 3 are each formed as a rectangular parallelepiped and have a flat top surface. Electricity generated in the battery cell 1 is supplied to an external device via the positive electrode terminal 4 and the negative electrode terminal 5, or electric power generated outside is supplied to a charging / discharging element via the positive electrode terminal 4 and the negative electrode terminal 5 for charging.

[0028] Next, the battery pack 10 will be described. The battery pack 10 is mounted, for example, in a hybrid vehicle driven by an internal combustion engine and a motor, or an electric vehicle driven by a motor, and is used as a drive source for the motor. As shown in FIG. 2, the battery pack 10 has a block 11 and a busbar case assembly 12.

[0029] (Block 11) As shown in Figs. 3 and 4, the block 11 includes a plurality of stacked battery cells 1 and spacers 21, a first end spacer 22, a second end spacer 23, a pair of side rails 24, 25, a pair of end plates 26, 27, and a plurality of bolts 28. The block 11 has a laminated structure in which the stacked battery cells 1 and the spacers 21 are integrated with each other. The length of the pair of side rails 24, 25 and the busbar case assembly 12 of the block 11 is constant, and when a regular-sized end member (not shown) is used instead of the second end spacer 23, the block 11 can hold a maximum number of battery cells 1, and when the second end spacer 23 is used, the block 11 can hold a number of battery cells 1 less than the maximum number. In other words, the number of battery cells 1 included in the block 11 can be changed without changing the length of the block 11 by changing the second end spacer 23 to one with a different thickness.

[0030] The spacers 21 are made of insulating synthetic resin and, as shown in Fig. 3, are sandwiched alternately between adjacent battery cells 1 and stacked together with the battery cells 1 in the X direction. Each spacer 21 has recesses on both sides that correspond to the shape of the battery cells 1, and the recesses hold the battery cells 1 and regulate the Y and Z directions. Additionally, the spacer 21 has claws on its upper part in the Z direction that fit into claws provided on a busbar case 35, which will be described later.

[0031] The first end spacer 22 is made of an insulating synthetic resin that is harder than the spacer 21, and is disposed opposite the battery cell 1 located at one end in the stacking direction. The first end spacer 22 has a recess corresponding to the shape of the battery cell 1 on the surface facing the battery cell 1, and the recess holds the battery cell 1 and regulates the Y and Z directions. In addition, a fixing bolt hole 22a and a negative electrode connection terminal 22b are provided on the side of the first end spacer 22 facing the end plate 27. Furthermore, a fixing bolt hole 22d is formed in the upper part of the first end spacer 22 in the Z direction for fixing each component.

[0032] The second end spacer 23 is made of a synthetic resin having insulation properties and a harder material than the spacer 21, and is disposed adjacent to the battery cell 1 located at the other end in the stacking direction. As shown in FIG. 3, the second end spacer 23 is formed with a plurality of rectangular cutout holes, preventing the occurrence of indentation after molding, so-called sink marks, and deformation. The second end spacer 23 has a concave portion corresponding to the battery cell 1 on the opposing surface facing the battery cell 1, and holds the battery cell 1 by the concave portion, regulating the Y direction and the Z direction.

[0033] On the side of the second end spacer 23 facing the end plate 26, a fixing bolt hole 23a, a positive electrode connection terminal 23b, and a gas discharge duct fixing hole 23d are formed. Note that the first end spacer 22 and the second end spacer 23 of the first embodiment correspond to the end members of the assembled battery according to an embodiment of the present invention. The fixing bolt holes 22a and 23a correspond to the fixing portions for fixing the assembled battery to the installation target. The positive electrode connection terminal 23b and the negative electrode connection terminal 22b correspond to connection terminals that are electrically connected to the single battery and electrically connected to the outside of the assembled battery. The gas discharge duct fixing hole 23d corresponds to the fixing portion of the gas discharge duct for discharging the gas that has come out of the single battery to the outside of the assembled battery.

[0034] In the second end spacer 23 of the first embodiment, the distance from the fixing bolt hole 23a to the opposing surface 23f facing the battery cell is equal to or greater than the thickness of the battery cell 1 in the stacking direction. In this embodiment, the second end spacer 23 is formed to be thicker in the stacking direction by the thickness of n stacked battery cells 1 than the regular-sized end member (regular end member) used when the number of cells is x. Here, x is the maximum number of battery cells 1 that can be stacked in the block 11, and n is an integer smaller than the number x of stacked battery cells 1, and is preferably an even number in order to minimize changes in components. That is, n and x are in the relationship of n < x. Also, the thickness of the n stacked battery cells 1 includes the thickness of the spacer sandwiched between the battery cells 1.

[0035] The second end spacer 23 has a configuration in which the length from each of the fixing bolt hole 23a, the positive electrode connection terminal 23b, and the gas exhaust duct fixing hole 23d to the opposing surface 23f facing the battery cell 1 is greater than that of the regular end member by an integer multiple of the thickness of the battery cell 1. For example, if the second end spacer 23 is configured to be twice as thick as the regular end member, it is possible to create a battery pack with two fewer cells than when the regular end member is used, and in a block 11 with 24 cells when the regular end member is used, it is possible to form a block 11 with 22 cells by using the second end spacer 23 instead of the regular end member.

[0036] The total length L24 of the regular end member, the 24 battery cells 1, and the spacer is the same as the total length L22 of the second end spacer 23, which is formed to be thicker by the width of two battery cells 1, and the 22 battery cells 1 and spacer (L24 = L22). The positions of the fixing bolt hole 23a, the positive electrode connection terminal 23b, and the gas exhaust duct fixing hole 23d of the second end spacer 23 are the same as those of the regular end member. As a result, even if the number of cells in the block 11 is reduced by two to 22, no design changes are required for the dimensions, shape, etc. of the components other than the second end spacer 23, and the components can be used as is.

[0037] In this embodiment, the case where the second end spacer 23 is thicker than the thickness of one battery cell 1 has been described, but a regular end member may be used instead of the second end spacer 23, and the first end spacer 22 may be formed to be thicker than the thickness of one battery cell. Also, both the first end spacer 22 and the second end spacer 23 may be made thicker than the thickness of one battery cell 1. In this case, the first end spacer 22 of the first embodiment corresponds to the first end plate or the second end plate of the battery pack according to one embodiment of the present invention, and the second end spacer 23 corresponds to the first end plate or the second end plate.

[0038] 3, the side rail 24 is made of a metal material and has a rail main body 24c extending in the X direction and bent portions 24b bent in the Y direction at both ends of the rail main body 24c to face each other, and each bent portion 24b is provided with a fixing hole 24a penetrating in the X direction. The bent portions 24b are disposed facing the first end spacer 22 and the second end spacer 23 from the outer side in the stacking direction, and cover a part of the first end spacer 22 and a part of the second end spacer 23.

[0039] The side rail 24 holds and fastens the first end spacer 22, the multiple battery cells 1, the multiple spacers 21, and the second end spacer 23 while pressing them in the stacking direction. The side rail 24 is fixed to the end plates 26, 27 by bolts 28 inserted through fixing holes 24a in the bent portions 24b. These bolts 28 are often made of metal.

[0040] The side rail 24 has a length that allows 22 battery cells 1 to be stacked when the second end spacer 23 is used. The side rail 25 has a similar shape to the side rail 24 and is a mirror image of the side rail 24. The side rail 25 is made of the same metal material as the side rail 24 and has the same function as the side rail 24. The side rail 25 is disposed opposite the side rail 24 in the Y direction with the stacked battery cells 1 between them, and has a rail main body 25c extending in the X direction and bent portions 25b bent in the Y direction at both ends of the rail main body 25c and facing each other. The bent portions 25b have fixing holes 25a through which bolts 28 are inserted. The pair of side rails 24, 25 in the first embodiment each correspond to a side member of a battery pack according to one embodiment of the present invention.

[0041] The end plate 26 is formed of a plate-shaped metal material, so-called sheet metal, and is disposed adjacent to the second end spacer 23 as shown in FIG. 3. The end plate 26 has a flat portion 26a in which a through hole for positioning with respect to the second end spacer 23 is formed, and a fixing portion 26b for fixing the side rail 24 and the side rail 25. The fixing portion 26b has a fixing hole 26c through which the bolt 28 is inserted. The fixing portion 26b has a step recessed in the stacking direction with respect to the flat portion 26a, and is configured so that when the bent portions 24b, 25b of the side rail 24 and the side rail 25 are fastened with the bolt 28, the head of the bolt does not protrude from the surface of the flat portion 26a. A nut is attached to the fixing portion 26b. The fixing portion 26b of the first embodiment corresponds to a connection portion with a side member of a battery pack according to one embodiment of the present invention.

[0042] End plate 27 is formed similarly to end plate 26, and is disposed adjacent to first end spacer 22, as shown in Fig. 4. End plate 27 and bent portions 24b, 25b of side rail 24 and side rail 25 are fastened together by bolts 28. The pair of end plates 26, 27 of the first embodiment each correspond to an end member of a battery pack according to one embodiment of the present invention.

[0043] (Busbar case assembly 12) 3, the busbar case assembly 12 is configured to include a busbar 31, a harness, a gas exhaust duct 234, multiple covers 34, and a busbar case 35. The busbar case assembly 12 has functions such as electrically connecting the terminals of the battery cells 1 to each other and to a controller, monitoring voltage and temperature, and exhausting gas.

[0044] 5, the bus bar 31 has an inter-cell bus bar 31a, a negative bus bar 31b, and a positive bus bar 31c, and each component is housed in a bus bar case 35. The inter-cell bus bar 31a is configured to electrically connect the positive terminal 4 and the negative terminal 5 of the battery cell 1. The negative bus bar 31b is connected to the second end spacer 23, and the positive bus bar 31c is connected to the first end spacer 22. Note that the negative bus bar 31b has a shape that is longer in the stacking direction of the battery cells 1 compared to the case of a regular end member.

[0045] The harness has a terminal portion, an electric wire portion, a temperature sensor portion, and a connector portion. The terminal portion electrically connects the bus bar 31 and the harness via the electric wire portion. The temperature sensor portion is in contact with the battery cover 3, measures the temperature of the battery cover 3, and outputs the measurement result. The connector portion is connected to each component, and connects each component to a controller (not shown). Each component is stored in a bus bar case 35.

[0046] The gas exhaust duct 334 has a gas exhaust port 233, and isolates and collects the gas exhausted from the gas exhaust valve 108b at the center in the Y direction of the busbar case 30 and exhausts it from the gas exhaust port 233. The gas exhaust duct 234 is fixed to the female threads of the first end spacer 22 and the second end spacer 23 with screws arranged at both ends in the X direction. The multiple covers 34 have the function of insulating and protecting the components of the busbar case assembly 12, and are arranged to cover the busbar 31 and harness. Each cover 34 is fitted into and fixed to the busbar case 35.

[0047] The busbar case 35 has multiple frames aligned in the stacking direction of the battery cells 1, and is configured to store the inter-cell bus bar 31a, the negative bus bar 31b, and the positive bus bar 31c within the frames. The busbar case 35 has multiple claw portions that are configured to fix the busbar case assembly 12 to the block 11 by fitting these claw portions into claw portions provided on the upper part of each spacer 21, first end spacer 22, and second end spacer 23 of the block 11 in the Z direction.

[0048] The effects of the battery pack 10 according to the first embodiment will be described.

[0049] The battery pack 10 according to the first embodiment has a second end spacer 23, which is formed to be thicker in the stacking direction than a regular end member used when the number of cells is x by the amount of n stacked battery cells 1. The overall length of the side rails 24, 25 is the same before and after the change in the number of battery cells 1 in the block 11, regardless of the change. The second end spacer 23 and the regular end spacer also have the same positions of the fixing bolt hole 23a, the positive electrode connection terminal 23b, and the gas exhaust duct fixing hole 23d.

[0050] As a result, it is possible to accommodate changes in the number of battery cells 1 by simply changing two components, the second end spacer 23 and the negative bus bar 31b that constitute the bus bar case assembly 12, and it is not necessary to change any other components of the battery pack 10. Note that by extending a portion of the negative bus bar 31b, it is not necessary to change the bus bar case 35. In the battery pack 10 according to this embodiment, it is possible to easily provide a combination of a battery pack with 24 battery cells 1 in the block 11 and a battery pack with 22 battery cells 1 in the block 11.

[0051] In a conventional battery pack, when the number of battery cells is changed, each component of the battery pack needs to be newly manufactured to match the number of cells. In this case, the assembly process and jigs change, and the settings of the manufacturing equipment need to be changed each time, which makes it difficult to share equipment, and increases the number of types of components and the number of management steps. In contrast, the battery pack 10 according to the first embodiment can minimize changes to the components even if the number of battery cells that make up the battery pack is changed. In addition, jigs and equipment can be shared, making it possible to minimize process changes and suppressing an increase in the number of management steps for the components, thereby providing the effect of solving the conventional problems.

[0052] The battery pack 10 according to the first embodiment has been described with respect to a structure in which the end plates 26 are made of sheet metal and the second end spacer 23 is thickened. The battery pack according to the first embodiment of the present invention may be configured with a structure other than that of the first embodiment. Battery packs 10A according to the second embodiment to battery packs 10D according to the fifth embodiment, which are configured with a structure other than that of the first embodiment, will be described below with reference to the drawings. Note that the same reference numerals are used for the same structures as those of the battery pack 10 according to the first embodiment, and detailed description thereof will be omitted.

[0053] Second embodiment Fig. 6 is a perspective view of the battery pack according to the second embodiment, and Fig. 7 is an exploded perspective view of the battery pack according to the second embodiment. A characteristic feature of this embodiment is that the fixing bolt holes 26Ab and the gas exhaust duct fixing holes 26Ae are provided in the end plate 26A, not in the end spacer 23A.

[0054] The battery pack 10A according to the second embodiment is composed of a block 11A and a busbar case assembly 12A, as shown in Fig. 6. The block 11A has multiple battery cells 1, multiple spacers 21, a first end spacer 22A, a second end spacer 23A, a pair of side rails 24, 25, a pair of end plates 26A, 27A, and multiple bolts 28, as shown in Fig. 7 and Fig. 8.

[0055] The first end spacer 22A has a flat opposing surface facing the end plate 27A on one side in the stacking direction, and has recesses formed on the other side in the stacking direction corresponding to the battery cells 1, which hold the battery cells 1 and regulate the Y and Z directions. The second end spacer 23A has a flat opposing surface facing the end plate 26A on the other side in the stacking direction, and has recesses formed on one side in the stacking direction corresponding to the battery cells 1, which hold the battery cells 1 and regulate the Y and Z directions.

[0056] The distance between the positive electrode connection terminal 26Ac and the opposing surface 23Af facing the battery cell 1, i.e., the thickness of the second end spacer 23A, is equal to or greater than the thickness in the stacking direction of the battery cells 1. In this embodiment, the second end spacer 23A is formed so that its thickness in the stacking direction is thicker than a regular-sized end member (regular end member) used when the number of cells is x by the amount of n stacked battery cells 1. The regular end member can have the same shape as the first end spacer 22A.

[0057] For example, in a block 11 with a maximum of 24 battery cells 1, if it is desired to change to a configuration in which the number of cells is reduced by two, a second end spacer 23A is used that is thicker by the amount of two stacked battery cells 1. Because the second end spacer 23A has a thickness equivalent to the reduction in the number of two battery cells 1 and the spacer 21 interposed between them, the position of the end plate 26A remains the same whether there are 24 or 22 battery cells 1. As a result, even if the number of cells in the block 11 is changed from 24 to 22, no design changes are required for the dimensions, shape, etc. of the components other than the second end spacer 23, and they can be used as is.

[0058] Whereas the end plate 26 of the first embodiment is made of a sheet metal member, the end plate 26A is made of a plate-shaped member made of die-cast aluminum. The end plate 26A is disposed facing the second end spacer 23A in the X direction, which is the stacking direction. The end plate 26A has a fixing portion 26Aa in which fixing bolt holes for fixing the side rails 24 and 25 are formed.

[0059] The end plate 26A is formed with a fixing bolt hole 26Ab and a gas exhaust duct fixing hole 26Ae. The fixing bolt hole 26Ab in the second embodiment corresponds to a fixing portion that fixes the battery pack to an installation target in the battery pack according to one embodiment of the present invention, and the gas exhaust duct fixing hole 26Ae corresponds to a discharge portion that discharges gas from inside the single cells to the outside of the battery pack.

[0060] The end plate 27A is formed similarly to the end plate 26A, and is disposed adjacent to the first end spacer 22A as shown in Fig. 8. The end plate 27A is formed with a fixing bolt hole 27Ab for fixing the battery pack 10A, a negative electrode connection terminal 27Ad, and a gas exhaust duct fixing hole 27Ae. The end plate 27A, the side rail 24, and the side rail 25 each have a bent portion 24b, 25b configured to be fastened by a bolt 28. The pair of end plates 26A, 27A of the second embodiment each correspond to an end member of the battery pack according to one embodiment of the present invention.

[0061] 7 and 8, the busbar case assembly 12A includes a busbar 31A, a harness, a gas exhaust duct 234 having a gas exhaust port 233, multiple covers 34A, and a busbar case 35A. When the number of cells x of the battery cells 1 is reduced by two to (x-2), the only change is to the negative busbar 31Ab of the busbar 31A, as in the first embodiment. The harness, cover 34A, and busbar case 35A have the same functions as the harness, cover 34, and busbar case 35 of the first embodiment.

[0062] In the battery pack 10A according to the second embodiment, the only changes associated with the change in the number x of the battery cells 1 are the second end spacer 23A and the negative electrode bus bar 31Ab, and the same effects as those of the battery pack 10 according to the first embodiment can be obtained.

[0063] Third embodiment 9 is an exploded perspective view of a battery pack according to the third embodiment. This embodiment is characterized in that the second end spacer 23B is thinner than the second end spacer 23A of the second embodiment, and the end plate 26B is thicker than the end plate 26A of the second embodiment.

[0064] 9, the battery pack 10B according to the third embodiment is composed of a block 11B and the same busbar case assembly 12A as in the second embodiment. Like the block 11A of the battery pack 10A according to the second embodiment, the block 11B has end plates 26B and end plates 27A formed by aluminum die casting, but differs from the block 11A in the shape of the second end spacer 23B and the shape of the end plate 26B.

[0065] The second end spacer 23B is of regular size with its thickness not extended, and has a recess formed on one surface in the stacking direction corresponding to the shape of the battery cell 1, while the surface facing the end plate 26B on the other surface in the stacking direction is formed flat.

[0066] The distance from the fixing bolt holes 26Bb to the opposing surface 26Bf of the end plate 26B that faces the second end spacer 23B is equal to or greater than the thickness in the stacking direction of the battery cells 1. In this embodiment, the end plate 26B is formed to be thicker in the stacking direction by the amount of n stacked battery cells 1 than a regular-sized end member (regular end member) used when the number of cells is x. The end plate 26B is disposed adjacent to the second end spacer 23B. The end plate 26B has a fixing portion 26Ba in which fixing bolt holes for fixing the side rail 24 and the side rail 25 are formed. The end plate 26B is formed with a fixing bolt hole 26Bb, a positive electrode connection terminal 26Bc, a negative electrode connection terminal 26Bd, and a gas exhaust duct fixing hole 26Be.

[0067] For example, in a block 11 capable of stacking a maximum of 24 battery cells 1, when the number of cells is reduced by two to 22, an end plate 26B is used that is formed thicker than a regular end member by the amount of two stacked battery cells 1. This allows the positions of the fixing bolt holes 26Bb, positive electrode connection terminal 26Bc, negative electrode connection terminal 26Bd, and gas exhaust duct fixing hole 26Be of the end plate 26B to be the same whether there are 24 or 22 battery cells 1. As a result, even if the number of cells in the block 11 is changed from 24 to 22, no design changes are required for the dimensions, shapes, etc. of the components other than the end plate 26B, and they can be used as is.

[0068] (Fourth embodiment) 10 is an exploded perspective view of a battery pack according to embodiment 4. A characteristic feature of this embodiment is that a block 11C uses dummy cells 1C as some of the multiple battery cells 1.

[0069] 10, the battery pack 10C according to the fourth embodiment has a block 11C. The second end spacer 23C and the end plate 26 are end members of the block 11C. They are of regular size and are used when the number of cells is up to x.

[0070] The dummy cells 1C have the same external dimensions as the battery cells 1, and are formed from a material such as an aluminum alloy. The dummy cells 1C are stacked adjacent to the battery cells 1, with n pieces of the battery cells 1 being equivalent. For example, in a reference block 11 in which x number of battery cells 1 are stacked, if the number of cells x is reduced by two to (x-2), two dummy cells 1C are stacked instead. As shown in FIG. 10, the two dummy cells 1C are arranged opposite each other with a spacer 21 in between.

[0071] In the battery pack 10C according to the fourth embodiment, the only changes associated with the change in the number x of the battery cells 1 are the dummy cells 1C and the negative bus bar 31b, and the same effects as those of the battery pack 10 according to the first embodiment can be obtained. For example, in a block 11 in which the number of battery cells 1 is stacked at 24, when the number of cells is reduced by two and changed to 22, by inserting two dummy cells, the positions of the fixing bolt hole 23Ca, the positive electrode connection terminal 23Cb, and the gas exhaust duct fixing hole 23Cd of the second end spacer 23C are the same whether the number of battery cells 1 is 24 or 22. Therefore, design changes such as dimensions and shapes of each component are not required, and the components can be used as they are.

[0072] Fifth embodiment Fig. 11 is a perspective view of a battery pack according to a fifth embodiment, and Fig. 12 is an exploded perspective view of the battery pack according to the fifth embodiment. A characteristic feature of this embodiment is that an extension spacer 21D is provided at the middle position in the stacking direction of multiple battery cells 1.

[0073] 11 and 12, the battery pack 10D has a block 11D. The block 11D is formed by stacking a plurality of battery cells 1. An extension spacer 21D is interposed at the middle position in the stacking direction of the plurality of battery cells 1.

[0074] The extension spacer 21D has a thickness equivalent to n battery cells 1. For example, in a block 11 capable of stacking a maximum of x battery cells 1, when the number of cells is reduced by two to (x-2), an extension spacer 21D is used that is formed to be thicker by the amount of two stacked battery cells 1. The extension spacer 21D is located at the middle position in the stacking direction in which the battery cells 1 and spacers 21 are alternately stacked, and is positioned toward one end side from the center part in the stacking direction.

[0075] The multiple battery cells 1 in the block 11D are divided into two in the stacking direction by an extension spacer 21D. A bus bar is attached so as to straddle the extension spacer 21D and connect the battery cells 1 to each other.

[0076] The extension spacer 21D may be composed of two or more extension spacers. In this case, the total thickness of the widths of the two or more extension spacers is formed to be thicker than the thickness of the battery cell 1. The extension spacer 21D is formed to be thicker than the other spacers 21. The extension spacer 21D may be disposed in a position other than the central portion. For example, one or two extension spacers may be disposed adjacent to the battery cell 1 closest to the second end spacer 23C or the first end spacer 22.

[0077] With the battery pack 10D of this embodiment, even if the number of battery cells 1 in the block 11D is reduced, the positions of the fixing bolt hole 23Ca, the positive electrode connecting terminal 23Cb, and the gas exhaust duct fixing hole 23Cd of the second end spacer 23C can be kept the same by using an extension spacer 21D with a thickness equivalent to the reduction in the number of battery cells 1. Therefore, there is no need to change the design of the dimensions, shapes, etc. of each component, and they can be used as is.

[0078] The battery pack 10 according to the first embodiment to the battery pack 10D according to the fifth embodiment are used as a single battery pack or as a power supply device in which a plurality of battery packs are arranged and electrically connected.

[0079] Next, power supply devices 40, 50 in which a plurality of assembled batteries 10E are arranged in a straight line in the stacking direction of the battery cells 1 will be described with reference to Figs.

[0080] FIG. 13 is a configuration diagram of a power supply device equipped with two assembled batteries each having a plurality of stacked battery cells, and FIG. 14 is a configuration diagram of a power supply device equipped with four assembled batteries each having a plurality of stacked battery cells.

[0081] As shown in Fig. 13, the power supply device 40 includes two assembled batteries 10E and a bus bar 40a that electrically connects the two assembled batteries 10E. The assembled battery 10E is configured similarly to the assembled battery 10 according to the first embodiment. The bus bar 40a connects the positive electrode Pe of the assembled battery 10E on one side and the negative electrode Ne of the assembled battery 10E on the other side, which are arranged opposite each other, and the two assembled batteries 10E are arranged in series in the closest proximity to each other via the bus bar 40a.

[0082] The battery pack 10E corresponds to the first or second battery pack of the battery pack according to one embodiment of the present invention, the stacking direction of the battery cells 1 corresponds to the first direction, and the bus bar 40a corresponds to the first bus bar. The power supply device 40 may be arranged such that the stacking directions of the battery cells 1 of the two battery packs 10E are perpendicular to each other. In this case, the perpendicular direction corresponds to the second direction of the battery pack according to one embodiment of the present invention. In the battery pack 10E, the first end spacer 22E is formed so that its thickness is twice the thickness of the battery cells 1. As a result, the battery pack 10 and the battery pack 10E have the same overall length.

[0083] This configuration allows the length of the bus bar 40a of the power supply device 40 to be minimized. When the power supply device 40 is mounted on a vehicle, it is disposed so as to straddle the left and right direction of the vehicle, for example, the battery pack 10E on one side is disposed below the left seat LS, and the battery pack 10E on the other side is disposed below the right seat RS. This provides the effect of making the weight balance of the vehicle uniform between the left and right sides.

[0084] 14, the power supply device 50 includes two power supply devices 40, a plate-shaped structure K fixed to the floor surface of a vehicle body (not shown), and a plurality of bolts (not shown) that fix the two power supply devices 40 to the structure K. The two power supply devices 40 are arranged in parallel so that the stacked battery cells 1 face each other. Centers of gravity G1, G2, G3, and G4, which serve as the first center of gravity of each assembled battery 10E, indicated by circles, are located away from the center of the stacking direction of the stacked battery cells 1 with respect to the bus bar 40a, and are set at the center of the width direction of the assembled battery 10E perpendicular to the stacking direction.

[0085] The center of gravity G0, which serves as the second center of gravity of the entire structure of the power supply device 50, is located at the center in the vehicle width direction. When mounted on a vehicle, the power supply device 50 is disposed so as to straddle the left and right directions of the vehicle, as indicated by the dashed line, with, for example, the left side of the power supply device 50 located below the left seat LS and the right side of the power supply device 50 located below the right seat RS. Therefore, the center of gravity G0 of the power supply device 50 is located at the center between the left and right seats. Note that the front-rear and left-right directions refer to the directions as seen by a vehicle occupant when seated in a seat.

[0086] With this configuration, the power supply device 50 and the power supply devices 40 are arranged in parallel, thereby saving space and achieving an even weight balance overall.

[0087] Based on the above explanation with reference to FIGS. 1 to 16, the following expressions are possible.

[0088] <Expression 1> A plurality of stacked unit cells; a first end member that holds the plurality of unit cells from one end side in the stacking direction; a second end member that holds the plurality of unit cells from the other end side in the stacking direction; and a connecting member connecting the first end member and the second end member; having the first end member protrudes from a connection position with the connecting member in the stacking direction toward the unit cell by a predetermined length, The predetermined length is equal to or greater than a thickness of the cells in a stacking direction.

[0089] <Expression 2> A plurality of stacked unit cells; a spacer that is stacked together with the plurality of battery cells; a holding member that holds the plurality of battery cells and the spacers in a stacking direction; having the holding member holds a plurality of battery cells and spacers over a constant overall length determined along the stacking direction; The spacer has a thickness in a stacking direction that is equal to or greater than a thickness of the unit cells in the stacking direction.

[0090] <Expression 3> A battery pack in which a plurality of unit cells are stacked, A pair of end members arranged opposite each other in a stacking direction of the plurality of unit cells; a pair of side members extending along the stacking direction and spaced apart from each other in a direction perpendicular to the stacking direction to connect the pair of end members to each other; The end member is an end plate connected to the side member; and an end spacer disposed between the end plate and the unit cell, the end plate has any one of a connection portion with the side member, a fixing portion that fixes the battery pack to an installation target, a connection terminal that is electrically connected to the cell and electrically connected to the outside of the battery pack, and an exhaust portion that exhausts gas emitted from inside the cell to the outside of the battery pack, a length from any one of said structures to a surface facing said battery cell in a stacking direction of said battery cell is greater than a thickness of said battery cell.

[0091] <Expression 4> A battery pack in which a plurality of unit cells are stacked, A pair of end members arranged opposite each other in a stacking direction of the plurality of unit cells; A pair of side members that are separated from each other in a direction orthogonal to the stacking direction and extend along the stacking direction to connect the pair of end members to each other. The end member includes An end plate that connects to the side member, and an end spacer that is disposed between the end plate and the single battery. The end spacer has any one of a connection portion with the side member, a fixing portion that fixes the assembled battery to an installation target, a connection terminal that is electrically connected to the single battery and electrically connected to the outside of the assembled battery, and a discharge portion that discharges gas emitted from the single battery to the outside of the assembled battery. An assembled battery, wherein in the stacking direction of the single batteries, the length from any one of the above configurations to the opposing surface facing the single battery is greater than the thickness of the single battery.

[0092] <Expression 5> The pair of side members have a length for stacking and arranging x single batteries when a regular end member is disposed at an end on one side in the stacking direction of the plurality of single batteries. The assembled battery according to Expression 3 or 4, wherein at least one of the pair of end members has a thickness in the stacking direction that is thicker than the regular end member by the thickness of n (n < x) single batteries.

[0093] <Expression 6> The assembled battery according to any one of Expressions 3 to 5, wherein the length greater than the thickness of the single battery is an integer multiple of the thickness of the single battery.

[0094] <Expression 7> The end member has a plurality of members disposed in the stacking direction of the single batteries. The assembled battery according to any one of Expressions 3 to 6, wherein the sum of the lengths in the stacking direction of two or more of the plurality of members is greater than the thickness in the stacking direction of the single battery.

[0095] <Expression 8> A plurality of single batteries to be stacked, end members disposed at both ends of the unit cells in a stacking direction; a side member arranged along a stacking direction of the unit cells and connected to the end member; having The end member is A first end member disposed at one end in the stacking direction; and a second end member disposed at the other end in the stacking direction, a first end member having a length in a stacking direction of the unit cells that is equal to or greater than a combined length of the second end member and a thickness of the unit cells;

[0096] <Expression 9> The end member is an end plate connected to the side member; an end spacer disposed between the end plate and the unit cell that is closest to the end plate in a stacking direction of the unit cells; The end plate or the end spacer is a first end plate or a first end spacer disposed at one end; a second end plate or a second end spacer disposed at the other end, the first end plate has a length in a stacking direction of the unit cells that is equal to or greater than a combined length of the second end plate and a thickness of the unit cells, Alternatively, the battery pack described in aspect 8 is characterized in that the first end spacer has a length equal to or greater than the combined length of the second end spacer and the thickness of the cell.

[0097] <Expression 10> A power supply device applied to a vehicle having a plurality of the assembled batteries according to Representation 8 or 9, the battery pack includes a first battery pack and a second battery pack including a plurality of unit cells stacked in a first direction along a stacking direction of unit cells of the first battery pack, the second assembled battery is disposed on a straight line along the first direction, or disposed in a second direction perpendicular to the straight line along the first direction, In the first direction, a first end member or a first bus bar of the first assembled battery is located closer to an end of the second assembled battery on the side where the first end member or the first bus bar is located than to another end of the first assembled battery.

[0098] <Expression 11> A power supply device for a vehicle including the battery pack according to claim 8 or 9 and a structure provided adjacent to the battery pack, the spacer is lighter than the unit cells and is disposed closer to one end than to a center in the stacking direction of the plurality of unit cells arranged in the stacking direction; a first center of gravity of the battery pack is located closer to the other end portion opposed to the one end portion in a stacking direction than the central portion; a second center of gravity formed by the battery pack and the structure when placed on the vehicle is located closer to the center in a vehicle width direction that intersects with the direction of travel of the vehicle than the first center of gravity of the battery pack when placed on the vehicle, the battery pack and the structure are placed on the vehicle such that the second center of gravity formed by the battery pack and the structure when placed on the vehicle is located closer to the center in a vehicle width direction that intersects with the direction of travel of the vehicle.

[0099] <Expression 12> A plurality of stacked unit cells; a spacer that is stacked together with the plurality of unit cells; end members located on both ends of the stacked plurality of unit cells and the spacer; a side member located along the stacking direction of the unit cells and connected to the end member, the side member holds the end member, the plurality of unit cells, and the spacer over a constant overall length determined along the stacking direction, the end member has any one of a connection portion with the side member, a fixing portion for fixing the battery pack to an installation target, a connection terminal for electrically connecting to the battery cell and for electrically connecting to the outside of the battery pack, and an exhaust portion for exhausting gas emitted from inside the battery cell to the outside of the battery pack, a thickness of the spacer in the stacking direction that is located between any one of the configurations and the unit cell farthest from any one of the configurations, with the unit cells arranged on both sides, is equal to or greater than a thickness of any one of the unit cells in the stacking direction.

[0100] <Expression 13> A plurality of stacked unit cells; A plurality of spacers stacked together with the plurality of unit cells; end members located on both ends of the stacked plurality of unit cells and the spacer; a side member located along the stacking direction of the unit cells and connected to the end member, the side member holds the end member, the plurality of unit cells, and the spacer over a constant overall length determined along the stacking direction, Among the plurality of spacers, a thickness of a first spacer in a stacking direction is greater than a thickness of a second spacer in the stacking direction, the first spacer is disposed closer to one end than to a center in the stacking direction of the plurality of unit cells arranged in the stacking direction, the second spacer is disposed closer to the other end portion opposed to the one end portion in the stacking direction than the central portion, and a difference between a thickness of the first spacer in the stacking direction and a thickness of the second spacer in the stacking direction is equal to or greater than a thickness of the single cell in the stacking direction.

[0101] <Expression 14> the spacer includes two or more spacers between adjacent cells in the stacking direction, or includes two or more spacers adjacent to the cell at an end of the stacking; The battery pack according to claim 12 or 13, wherein the total length of thicknesses of the two or more spacers in the stacking direction is greater than or equal to the thickness of the unit cells in the stacking direction.

[0102] <Expression 15> the first spacer has a thickness in the stacking direction that is equal to or greater than a thickness in the stacking direction of any one of the unit cells, The first spacer has a surface perpendicular to the stacking direction, The battery pack described in expression 12 or 13, wherein a first width in a first direction is equal to or smaller than the first width of the second spacer, or a second width in a second direction perpendicular to the first direction is equal to or smaller than the second width of the second spacer.

[0103] Although the embodiment of Example 1 of the present invention has been described in detail above, this example is not limited to the above embodiment, and various design changes can be made within the scope of the spirit of the present invention described in the claims. For example, the above-mentioned embodiment has been described in detail to explain the present invention in an easy-to-understand manner, and is not necessarily limited to having all of the configurations described. In addition, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Furthermore, it is possible to add, delete, or replace a part of the configuration of each embodiment with another configuration. EXAMPLES

[0104] A typical battery pack has a structure in which a block of multiple stacked battery cells is held by metal plates. A number of battery packs are then stored and fixed in a metal container and installed in vehicles, etc., as a battery pack.

[0105] In a conventional battery pack, a metal side plate is connected to a metal end plate arranged at the outermost part of a cell stack, and the battery cells are tightly held together. The end plate is then fixed to a metal container connected to earth to form a battery pack. The side plate is electrically conductive to the container. However, if the side plate is left as bare metal, when the battery pack is immersed in salt water, a short circuit occurs between the side plate connected to earth and the battery cells through the salt water, which may lead to a sudden reaction. To address this problem, conventionally, the side plate has been insulated to prevent a short circuit between the battery cells and the side plate. However, there is a problem in that insulating the side plate increases costs.

[0106] To solve these problems, this embodiment is configured to keep the metallic battery pack container, which is connected to earth, and the side plate insulated from each other, mitigating the current between the battery cells and the side plate and suppressing sudden reactions, even in cases where the battery pack is immersed in salt water.

[0107] This embodiment can be applied not only to the structure of the first embodiment, but also to a normal battery pack. Therefore, the following description will be given of the case where this embodiment is applied to a normal battery pack. The specific configuration is as follows. That is, the parts that fix the battery pack to the metal container are changed from metallic end spacers to resin end spacers, thereby maintaining the insulation between the battery pack container and the battery cells. This configuration is also described in, for example, Figures 3 and 4 and paragraphs 0024 to 0027 of the first embodiment. A metallic collar is inserted into the resin end spacer, and the battery pack is fastened to the battery pack container by a bolt that penetrates the collar.

[0108] The battery cells are stacked in a first direction, and the stack is held so as to be surrounded by two end plates and two side plates. That is, the stack of battery cells is bolted in the first direction by the end plates and side plates to hold and fix the battery cells. The side plates are electrically insulated from the metal container. That is, since the end spacers are made of an insulator, the side plates or the battery pack container are insulated from the battery cells. Therefore, even if a battery pack having multiple assembled batteries is immersed in salt water, the current flowing between the battery cells and the battery pack container is mitigated, and a sudden reaction caused by a large current flow is also suppressed.

[0109] In order to ensure insulation between the side plates and the battery cells, protruding ribs are formed on the spacers inserted between the battery cells, enabling the spacing between the side plates and the battery cells to be maintained.

[0110] A specific configuration of the second embodiment will be described below with reference to the drawings. FIG. 17 is an external view of the battery pack 10 in the second embodiment. The battery pack 10 shown in FIG. 17 has substantially the same external appearance as the configuration shown in FIG. 2 and the like in the first embodiment. However, the configuration of the second embodiment can be used not only for the battery pack 10 in the first embodiment, but also for a normal battery pack 10 that does not use the configuration of the first embodiment. Therefore, the configuration of the battery pack 10 shown below is not particularly limited to the configuration of the first embodiment.

[0111] Fig. 18 is an exploded perspective view showing the battery pack 10 in Fig. 17 disassembled into a block 11 and a busbar case assembly 12. Fig. 19 is an exploded perspective view of the block 11. As shown in Fig. 19, the longitudinal direction of the block 11 is defined as the X direction (or stacking direction), the up-down direction is defined as the Z direction, and the direction perpendicular to the X direction and Z direction is defined as the Y direction.

[0112] The harness 32 has a terminal portion, an electric wire portion, a temperature sensor portion, and a connector portion. The terminal portion electrically connects the bus bar and the harness via the electric wire portion. The temperature sensor portion is in contact with the battery cover, measures the temperature of the battery cover, and outputs the measurement result. The connector portion is connected to each component, and connects each component to a controller (not shown). The harness of the first embodiment can be the same.

[0113] As shown in Figures 17 to 19, the battery pack 10 is composed of a block 11 having multiple battery cells 101 and a mechanism for integrating them, and a busbar case assembly 12 consisting of harnesses for electrically connecting the terminals of the battery cells 101 and for monitoring the voltage and temperature, etc.

[0114] 19, the block 11 is arranged in the Y direction with a pair of side plates 120, battery cells 101, and multiple spacers 121 stacked alternately in the X direction. Next to the battery cells 101 located at both ends in the X direction, there is a negative electrode end spacer 122 on the -X direction side, a positive electrode end spacer 123 in the +X direction, and end plates 124 and multiple bolts 125 arranged on both sides of them.

[0115] The spacers 121, N-end spacer (negative electrode end spacer) 122, and P-end spacer (positive electrode end spacer) 123 are made of insulating resin. The stacked battery cells 101 are held by grooves provided in the spacers 121, N-end spacer 122, and P-end spacer 123 that correspond to the battery cells 101 and regulate the X and Y directions.

[0116] The end plate 124 is a rectangular flat steel plate extending in the Y direction, and has two nuts attached in each direction in the X direction by caulking or the like.

[0117] The side plate 120 is a steel plate having a flange extending in the Y direction, a hole penetrating in the X direction, and a wide surface facing in the Y direction that is largely open.

[0118] The multiple battery cells 101, spacers 121, N-end spacer 122, and P-end spacer 123 are sandwiched between a pair of end plates 124, and this stack is held and fastened in a compressed state by a pair of side plates 120. The side plates 120 are fastened and fixed to nuts provided on the end plates 124 by bolts 125.

[0119] 20 is an external perspective view of the N-end spacer 122. In order to house and fix the battery pack 10 housing the block 11 in a battery pack container (hereinafter also referred to as a container), a metallic collar 126 having a through hole 126a for a through bolt and a metallic collar 127 having a through hole 127a are arranged on the N-end spacer 122. When fixing the block 11 to the container, a bolt is passed through the through holes 126a, 127a of the collars 126, 127 to fasten them.

[0120] Fig. 21 is a side view of the block 11. Fig. 22 is a cross-sectional view taken along line AA in Fig. 21. In Fig. 22, the side plate 120 and the end plate 124 are in contact with each other at the insulating resin portion of the N end spacer 122, and are not in contact with the collars 126 and 127. In other words, the side plate 120 and the end plate 124 are electrically insulated from the collars 126 and 127. Therefore, the side plate 120 is also insulated from the container of the battery pack.

[0121] Figure 23 is a front view of the spacer 121. The spacer 121 has ribs 121a, 121b, 121c, and 121d, and is designed to maintain a constant distance between the battery cell 101 and the side plate 120, as indicated by x and y in Figure 22. In other words, the ribs 121a, 121b, 121c, and 121d make it possible to set the necessary distance so that the battery cell 101 and the side plate 120 are sufficiently insulated from each other.

[0122] With the above-described configuration, even if the battery pack is immersed in salt water, the side plate 120 is not connected to earth, so that the current flowing between the battery pack and the battery cell 101 via the salt water can be mitigated, thereby suppressing a sudden reaction. Also, a connection portion 121e is formed on the upper side facing the busbar case assembly 12. For example, a claw-like protrusion is formed. A fixing portion is provided for fixing the connection portion 121e to the facing busbar case 35. In the present embodiment, an example in which the connection portion 121e is provided on each spacer is shown, but this is not limited to this, and spacers having the connection portion 121e may be arranged at intervals. This contributes to fixing the block 11 and the busbar case assembly 12. The resin spacer 121 is fitted into the resin busbar case 35 and fixed. This makes it possible to suppress unnecessary electrical conduction between the assembled battery and surrounding members.

[0123] Fig. 24 is a cross-sectional view showing another configuration in which the battery body is fastened in the stacking direction by the side plate 120 and the end spacer 122. Fig. 24 is a schematic cross-sectional view corresponding to the vicinity of the N end spacer 122 in Fig. 22. Fig. 24 shows a structure in which the end spacer 122 made of insulating resin is directly connected to the side plate 120. That is, an insert nut is embedded in advance in the hole in the end plate 122 into which the bolt 125 is inserted. Then, the side plate 120 and the end plate 124 are directly fastened in the X direction by the bolt.

[0124] In Fig. 24, a metallic collar 126 having a through hole 126a for a through bolt and a metallic collar 127 having a through hole 127a are arranged on an end spacer 122 in order to house and fix the assembled battery in a battery pack container. The collars 126 and 127, which have the same potential as the container, are insulated from the side plate 120. Therefore, the side plate 120 is insulated from the battery pack container. Also, as shown in Fig. 19, the side plate 120 is insulated from both the battery pack and the battery cells 101. Therefore, even if the assembled battery is immersed in salt water, the current flowing between the battery cells 101 and the side plate 120 can be mitigated, and a sudden reaction can be suppressed.

[0125] FIG. 25 is a cross-sectional view showing yet another configuration in which the battery body is fastened in the stacking direction by the side plate 120 and the end spacer 122. FIG. 25 is a schematic cross-sectional view, and corresponds to the vicinity of the end spacer 122 in FIG. 22. In FIG. 25, the end plate 122 is formed not from a metal plate but from, for example, aluminum die casting. By using die casting, the end plate 124 can be formed in a relatively free shape. In FIG. 25, the end plate 124 is disposed on the outside of the end spacer 122. In FIG. 25, the plate thickness of the end plate 124 is made thicker at the portion where the bolt 125 is screwed, and a female screw is formed directly in this portion. Therefore, the end plate 124 and the side plate 120 can be fastened together even if a nut or the like is not separately formed by caulking or the like. In FIG. 25, the end plate 124 and the side plate 120 are fastened together in the X direction by the bolt 125.

[0126] 25, metallic collar 126 having through hole 126a for a through bolt and metallic collar 127 having through hole 127a are also arranged to house and secure the assembled battery in the battery pack container. Collars 126, 127, which have the same potential as the container, are insulated from side plate 120. Therefore, even if the assembled battery is immersed in salt water, the current flowing between battery cells 101 and side plate 120 can be mitigated, and the occurrence of a sudden reaction can be suppressed.

[0127] Fig. 26 is a cross-sectional view showing yet another configuration in which the battery body is fastened in the stacking direction by the side plate 120 and the end spacer 122. Fig. 26 is a schematic cross-sectional view that corresponds to the vicinity of the end spacer 122 in Fig. 22. Fig. 26 is the same as Fig. 25 in that the end plate 124 is formed not from a metal plate but, for example, by aluminum die casting. Fig. 26 differs from Fig. 25 in that the end plate 124 is disposed inside the end spacer 122. By die casting, the end plate 124 can be formed in a relatively free shape, so the shape can be changed to match the shape of the inside or outside of the end spacer 124.

[0128] 26, the portion of end plate 124 where bolt 125 is screwed is made thicker, and a female thread is formed directly in this portion. Therefore, end plate 124 and side plate 120 can be fastened together without the need for a separate nut or the like formed by caulking or the like. In Fig. 26, end plate 124 and side plate 120 are fastened together in the X direction by bolt 125 so as to sandwich end spacer 122.

[0129] 26, metallic collar 126 having through hole 126a for a through bolt and metallic collar 127 having through hole 127a are also arranged to house and secure the assembled battery in the battery pack container. Collars 126, 127, which have the same potential as the container, are insulated from side plate 120. Therefore, even if the assembled battery is immersed in salt water, the current flowing between battery cells 101 and side plate 120 can be mitigated, and the occurrence of a sudden reaction can be suppressed. [Explanation of symbols]

[0130] 1: battery cell (single cell), 2: battery can, 10, 10A, 10B, 10C, 10D, 10E: assembled battery, 11: block, 12: busbar case assembly, 21: spacer (second spacer), 21D: extension spacer (first spacer), 22: first end spacer (regular end member), 22a, 23a, 23Ca, 26Ab, 26Bb, 27Ab: fixing bolt holes, 23, 23A, 23B, 23C: second end spacer (end member), 24, 25: side rail (side member), 26, 26A, 26B, 27, 27A: end plate (end member), 26a: flat portion, 26b, 26Aa, 26Ba, 27Aa: fixing portion, 28: bolt, 31, 40a: bus bar, 233: gas exhaust portion, 34: cover, 35: bus bar case, 40, 50: power supply unit, G0: center of gravity (second center of gravity), G1, G2, G3, G4: center of gravity (first center of gravity), 101: battery cell (single cell), 120: side plate, 121: spacer, 121a: rib, 121b: rib, 121c: rib, 121d: rib, 122: N end spacer, 123: P end spacer, 124: end plate, 125: bolt, 126: collar, 126a: through hole, 127: collar, 127a: through hole

Claims

1. A battery body in which a plurality of unit cells are stacked; a pair of end members having an insulating material and arranged on both sides of the battery body in a stacking direction of the unit cells of the battery body; a pair of side plates, each of which is disposed on one side surface of the battery body in the stacking direction of the unit cells and connected to the end members, the side plates having a metal material, the end member includes a fastening portion that receives a fastening member that fastens the battery pack to a mounting object, The fastening portion and the side plate are disposed so as not to be electrically connected to each other, The end member is a pair of end plates having connection portions with the side plates and made of a metal material; and a pair of end spacers having the fastening portions and made of an insulating material, the end plate and the side plate are fastened together at the connection portion disposed inside the end spacer when viewed in the stacking direction of the unit cells so as to fasten the plurality of unit cells in the stacking direction; The battery pack according to claim 1, wherein the side plate is not electrically conductive to the fastening member.

2. In the battery pack according to claim 1, The battery pack according to claim 1, wherein the fastening members are metal bolts.

3. In the battery pack according to claim 1, a side surface of the battery body in the stacking direction of the unit cells and the side plate are disposed with a gap therebetween and are electrically insulated from each other.

4. A battery body having a plurality of stacked single cells; a pair of end members having an insulating material and arranged on both sides of the battery body in a stacking direction of the unit cells of the battery body; a pair of side plates, each of which is disposed on one side surface of the battery body in the stacking direction of the unit cells and connected to the end members, the side plates having a metal material, the end member includes a fastening portion that receives a fastening member that fastens the battery pack to a mounting object, The fastening portion and the side plate are disposed so as not to be electrically connected to each other, The end member is an end plate connected to the side plate; and an end spacer disposed between the end plate and the battery cell; The end plate is a connection portion with the side plate, a fixing portion for fixing the battery pack to an installation target, a connection terminal for electrically connecting to the battery cell and electrically connecting to the outside of the battery pack, and an exhaust portion for exhausting gas emitted from the battery cell to the outside of the battery pack, a length from any one of the structures to a surface facing the single cells in the stacking direction of the single cells is greater than a thickness of the single cells.

5. A battery body having a plurality of stacked single cells; a pair of end members having an insulating material and arranged on both sides of the battery body in a stacking direction of the unit cells of the battery body; a pair of side plates, each of which is disposed on one side surface of the battery body in the stacking direction of the unit cells and connected to the end members, the side plates having a metal material, the end member includes a fastening portion that receives a fastening member that fastens the battery pack to a mounting object, The fastening portion and the side plate are disposed so as not to be electrically connected to each other, The end member is A first end member disposed at one end in the stacking direction; A second end member is disposed at the other end in the stacking direction, a first end member having a length equal to or greater than a combined length of the second end member and a thickness of the battery cell in the stacking direction of the battery cell;

6. A battery body having a plurality of stacked single cells; a pair of end members having an insulating material and arranged on both sides of the battery body in a stacking direction of the unit cells of the battery body; a pair of side plates, each of which is disposed on one side surface of the battery body in the stacking direction of the unit cells and connected to the end members, the side plates having a metal material, the end member includes a fastening portion that receives a fastening member that fastens the battery pack to a mounting object, The fastening portion and the side plate are disposed so as not to be electrically connected to each other, The end member is an end plate connected to the side plate; an end spacer disposed between the end plate and the unit cell that is closest to the end plate in a stacking direction of the unit cells; The end plate or the end spacer is a first end plate or a first end spacer disposed at one end; a second end plate or a second end spacer disposed at the other end, the first end plate has a length in the stacking direction of the unit cells that is equal to or greater than a combined length of the second end plate and a thickness of the unit cells, Alternatively, the first end spacer has a length equal to or greater than a combined length of the second end spacer and a thickness of the cell.

7. A power supply device applied to a vehicle equipped with a plurality of assembled batteries, The plurality of assembled batteries are the assembled batteries according to claim 5 or 6, the plurality of assembled batteries include a first assembled battery and a second assembled battery, and when a stacking direction of the unit cells of the first assembled battery is defined as a first direction, the second assembled battery is disposed such that the unit cells of the second assembled battery are positioned on a straight line along the first direction; The power supply device is further characterized in that the end member arranged on one side of the first assembled battery and the end member arranged on one side of the second assembled battery are arranged to face each other, and the positive electrode of the first assembled battery and the negative electrode of the second assembled battery are connected by a bus bar.

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